/Engine/Plugins/Online/OnlineSubsystemUtils/Source/OnlineSubsystemUtils/Public/VoipListenerSynthComponent.h
Thread safe way to get whether this synth component still has buffered packets of audio to play back. This function is used by the Voice Engine to clean up voice sounds when they are not playing back audio to make space for other sounds to be rendered.
true if this synth component is out of audio to play.
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="Audio|Voice|Sender") bool IsIdling()